Chip-mounted film package

ABSTRACT

A chip-mounted film package includes a base film, an effective film package defined on the base film by a cutting line, a driving chip mounted on the effective film package, a plurality of input pads arranged on an input area of the effective film package and connected to the driving chip, and a plurality of output pads arranged on an output area of the effective film package and connected to the driving chip, wherein the output area includes at least one extended portion that protrudes from a side of the effective film package in a horizontal direction of the base film.

This application claims the benefit of Korean Patent Application No.P2003-99803 filed in Korea on Dec. 30, 2003, which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display module, andmore particularly to a chip-mounted film package of the liquid crystaldisplay module.

2. Discussion of the Related Art

Generally, a liquid crystal display (LCD) employs an electric field tocontrol light transmittance through a liquid crystal having a dielectricanisotropy, thereby displaying a picture. Specifically, the LCD includesan LCD panel for displaying a picture, and a driving circuit for drivingthe LCD panel. In the LCD panel, liquid crystal cells are arranged in amatrix to control light transmittance in accordance with pixel signals,thereby displaying a picture. The driving circuit includes a gate driverfor driving gate lines of the LCD panel, a data driver for driving thedata lines, a timing controller for controlling a driving timing of thegate driver and the data driver, and a power supply for supplying powersignals required for driving the LCD panel and the driving circuit.

The data driver and the gate driver are separated into a plurality ofdrive integrated circuits (D-ICs). Each of the D-ICs is mounted on anopened IC area of a tape carrier package (TCP) or on a base film of theTCP by a chip on film (COF) system, to thereby be electrically connectedto the LCD panel by a tape automated bonding (TAB) system.Alternatively, the D-IC may be directly mounted on the LCD panel by achip on glass (COG) system. Since the TAB system ensures that arelatively wide pixel matrix area from the LCD panel has an easyattachment process, it has been mainly used.

FIG. 1 is a plan view schematically illustrating a rear structure of arelated art LCD module. As shown in FIG. 1, the related art LCD moduleincludes a data TCP (or COF) 12 and a gate TCP (or COF) 16. The data TCP12 (or COF) is connected between a data PCB 20 and an LCD panel 10 andhas a data D-IC 14 mounted thereon. On the other hand, the gate TCP (orCOF) 16 is connected between a gate PCB 22 and the LCD panel 10 and hasa gate C-IC 18 mounted thereon.

The LCD panel 10 has a thin film transistor array substrate and a colorfilter array substrate that are bonded to each other with a liquidcrystal layer therebetween. The LCD panel 10 includes liquid crystalcells between gate lines and data lines. Each of the liquid crystalcells includes a thin film transistor as a switching device. The thinfilm transistor applies a pixel signal from the data line in response toa scanning signal from the gate line.

The data D-IC 14 is connected to the data line of the LCD panel 10 viathe data TCP (or COF) 12. The data D-IC 14 converts a digital pixel datasignal from an external timing controller (not shown) into an analogpixel signal and applies the analog pixel signal to the data line. Onthe other hand, the gate D-IC 18 is connected to the gate line of theLCD panel 10 via the gate TCP (or COF) 16. The gate D-IC 10 supplies aturn-on voltage of the thin film transistor to the gate line during acorresponding scan period while supplying a turn-off voltage of the thinfilm transistor to the gate line during the remaining period.

The data TCP (or COF) 12 and the gate TCP(or COF) 16 shown in FIG. 1 areprepared on a roll-type base TCP and then are molded by a cuttingprocess. FIG. 2 is a plan view showing the data TCP (or COF) 12 beforethe cutting process of the related art LCD module. As shown in FIG. 2,the data TCP (or COF) 12 is provided on a base film 32 of the roll-typebase TCP 30. The base film 32 is usually made of polyimide. The data TCP(or COF) 12 has the data D-IC 14 mounted thereon, and is also providedwith a plurality of input pads IP connected to input pins of the dataD-IC 14 and a plurality of output pads OP connected to output pinsthereof. Further, a sprocket hole 34 is provided in a line along thevertical direction at each side of the base film 32 so as to deliver thebase film 32 and determine a delivery position.

The data TCP (or COF) 12 is molded by a process of cutting the base TCP30 along a cutting line CL. The molded data TCP (or COF) 12 is attachedto the LCD panel 10 shown in FIG. 1 and to the data PCB 20 by ananisotropic conductive film ACF. A first aligning mark 15 adjacent tothe input pad IP is provided within the data TCP (or COF) 12 so as tomake an alignment of the data TCP (or COF) 12 with the data PCB 20. Asecond aligning mark 17 adjacent to the output pad OP is provided withinthe data TCP (or COF) 12 so as to make an alignment of the data TCP (orCOF) 12 with the LCD panel 10.

The data TCP (or COF) 12 is provided on the base TCP 32 generally havinga normal horizontal width of 35mm as shown in FIG. 2 such that the dataTCP (or COF) 12 has 384 output pads OP, namely, 384 output channels inlight of manufacturing costs. In this case, the data TCP (or COF) 12 hasan effective horizontal width of about 27 mm excluding a dummy areawhere the sprocket hole 34 are formed on the base TCP 30. Moreover, the384 output pads OP of the data TCP(or COF) 12 are provided in parallelto each other at a pitch P1 of about 60 μm in light of reliability andprocess tolerance. The 384 output channels of the data TCP (or COF) 12correspond to output channels of the data D-IC 14.

In order to reduce manufacturing costs by reducing the number of thedata TCP (or COF) 12 and the data D-IC 14 that are expensive, the numberof the output channels of the data TCP (or COF) 12 and the data D-IC 14should be increased. For instance, when the LCD panel 10 has a XGA classresolution of 1024×768 pixels, it is provided with total 3072 data linesin light of R, G and B sub-pixel included per pixel. If the 3072 datalines are intended to be driven by the data D-IC 14 having the 384output channels shown in FIG. 2, then the LCD panel 10 of FIG. 1 mustinclude 8 (i.e., 3072/384=8) data D-ICs 14 and 8 data TCPs (or COFs) 12mounted with them. However, the data D-IC 14 includes a digital toanalog converter (DAC) having a complex structure proportional to thenumber of data lines in order to convert 6-bit or 8-bit pixel datasupplied per data line into analog pixel signals. Thus, once the numberof the output channels of the data D-ICs 14 is increased, the circuitstructure becomes complex and difficult to enlarge a chip area as wellas an area of the data TCP (or COF) 12 mounted with the data D-IC 14.Moreover, the TCP (or COF) has a relatively high cost with respect to anarea thereof Thus, there is a problem in that, once the number of theoutput channels of the data D-IC 14 is increased, an area of the TCP (orCOF) is enlarged, which makes the manufacturing costs rise more.

In order to overcome this problem, a proposal has been made to reduce anarea occupied by the DAC circuit by using a time-divisional driving ofthe data lines so as to increase the number of output channels of thedata D-ICs while controlling the chip area, thereby reducing the numberof the D-ICs and TCPs, as disclosed in Korea Patent Application No.2002-41769. However, since the number of the output channels of the dataD-ICs are increased by twice when the number of the data D-ICs isreduced to a half (½) and hence an area occupied by the output padsinstead of the D-ICs is enlarged, it becomes necessary to provide a baseTCP having a larger dimension than the existent 35 mm base TCP. Moreoverif a 70 mm TCP instead of the 35 mm TCP is used for the purpose ofincreasing the number of the output channels per TCP by twice, thenthere is a problem in that an expensive TCP also leads to an increase ofthe manufacturing costs.

In order to solve this problem, a strategy has been proposed to reduce adistance between the output channels within the TCP (or COF) to increasethe number of output channel per unit area. However, this strategy has alimitation in that reducing a distance between the output pads can onlybe done to certain degree in light of reliability and manufacturingprocess tolerances. Moreover, an effective area to be occupied by thedata TCP (or COF) 12 is further reduced even on the 35 mm base TCP 30 asshown in FIG. 2 due to the dummy area for forming the sprocket holes 34to thereby have a horizontal width of about 27 mm. As a result, the dataTCP (or COF) 12 having an effective horizontal width of 27 mm as shownin FIG. 2 is limited to an increase of 384 output pads OP provided at apitch P1 of about 60 μm, that is, the number of the output channels.

Therefore, there is a desire to enlarge an effective area of the dataTCP (or COF) 12 without enlarging the base TCP (or COF), which adverselyaffects the manufacturing costs, thereby increasing the number of theoutput channels.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a chip-mounted filmpackage that substantially obviates one or more of the problems due tolimitations an disadvantages of the related art.

An object of the present invention is to provide a chip-mounted filmpackage having an enlarged effective area within a base TCP (or COF).

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, thechip-mounted film package includes a base film including a cutting line,an effective film package defined on the base film by the cutting lineand including input area and output area, a driving chip mounted on theeffective film package, a plurality of input pads arranged on the inputarea of the effective film package and connected to the driving chip,and a plurality of output pads arranged on the output area of theeffective film package and connected to the driving chip, wherein theoutput area includes at least one extended portion that protrudes from aside of the effective film package in a horizontal direction of the basefilm.

In another aspect, the chip-mounted film package includes a base filmincluding a dummy area and a cutting line, the dummy area being outsideof the cutting line, an effective film package defined on the base filmby the cutting line, the effective film package having input pads andoutput pads, a driving chip mounted on the effective film package andconnected to the input and output pads of the effective film package, aplurality of sprocket holes arranged in the dummy area in a horizontaldirection of the base film.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a plan view schematically illustrating a rear structure of arelated art LCD module;

FIG. 2 is a plan view showing a data TCP (or COF) before a cuttingprocess of the data TPC (or COF) of the related art LCD module;

FIG. 3 is a plan view showing a structure of a TCP (or COF) according toa first embodiment of the present invention;

FIG. 4 is a plan view showing a structure of a TCP (or COF) according toa second embodiment of the present invention;

FIG. 5 is a plan view showing a structure of a TCP (or COF) according toa third embodiment of the present invention; and

FIG. 6 is a plan view showing a rear structure of an LCD panel adoptingthe TCP (or COF) according to any one of the three exemplary embodimentsof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIG. 3 is a plan view showing a roll-type base TCP (or COF) 50 providedwith an effective TCP (or COF) 42 according to a first embodiment of thepresent invention. Herein, the effective TCP (or COF) 42 corresponds toa data TCP mounted with a data D-IC or a gate TCP mounted with a gateD-IC.

As shown in FIG. 3, the effective TCP (or COF) 42 is provided on a basefilm 52 of the roll-type base TCP (or COF) 50. The base film 52 isusually made of polyimide. An area of the effective TCP (or COF) 42 atthe base TCP (or COF) 50 is determined by a cutting line CL. Theeffective TCP (or COF) 42 is molded by a process of cutting the base TCP(or COF) 50 along the cutting line CL. The base film 52 is deliveredinto a dummy area positioned at the outer side of the effective TCP (orCOF) 42, namely, the cutting line CL. A sprocket hole 54 for determiningthe delivery position is provided along a line on the dummy area asshown in FIG. 3.

The effective TCP (or COF) 42 is mounted with a data D-IC 44, and isprovided with a plurality of input pads IP connected to input pins ofthe data D-IC 44 and a plurality of output pads OP connected to outputpins thereof Further, the effective TCP (or COF) 42 includes an extendedportion 46 that protrudes from sides of the effective TCP (or COF) 42 ina horizontal direction so as to enlarge an effective area of theeffective TCP (or COF) 42 at which the output pads OP are able to beformed on the 35mm base TCP (or COF) 50. In this exemplary embodiment, adistance between the sprocket holes 54 is increased such that theextended portion 46 does not interfere with the sprocket holes 54,thereby positioning the extended portion 46 between the sprocket holes54. Or at least one of sprocket holes 54 is removed so as to leave aspace for forming the extended portion 46. Thus, the extended portion 46is extended into the edge of the base TCP (or COF) 50, thereby allowingthe output pads OP of the effective TCP (or COF) 42 to be formed on anenlarged effective area with a horizontal width (i.e., 35 mm) of thebase TCP (or COF) 50. Thus, it becomes possible to enlarge the effectivearea for forming the output pads OP of the effective TCP (or COF) 42without enlarging the horizontal width of the base TCP (or COF) 50. As aresult, it is possible to increase the number of output pads OP that areformed within the effective TCP (or COF) 42.

The data TCP (or COF) 42 molded along the cutting line CL is attachedbetween a data PCB 60 (of FIG. 6) and an LCD panel 40 (of FIG. 6) byusing an anisotropic conductive film ACF. In this exemplary embodiment,a first aligning mark 45 adjacent to the input pad IP is provided withinthe data TCP (or COF) 42 so as to make an alignment of the data TCP (orCOF) 42 with the data PCB 60. A second aligning mark 47 adjacent to theoutput pad OP is provided within the data TCP (or COF) 42 so as to makean alignment of the data TCP (or COF) 42 with the LCD panel 40.

FIG. 4 is a plan view showing of a base TCP (or COF) provided with aneffective TCP (or COF) according to a second exemplary embodiment. Asshown in FIG. 4, sprocket holes 74 of a base film 72 are provided alonga line in the horizontal direction in a dummy area positioned at anouter side of the effective TCP (or COF) 42 defined by the cutting lineCL. In other words, the sprocket holes 74 are provided in the horizontaldirection in the dummy area between the effective TCPs (or COFs) 42.Thus, the effective TCP (or COF) 42 has a horizontal width equal to thehorizontal width (i.e., 35 mm) of the base TCP (or COF) 50. The outputpads OP are also arranged on the extended portion 46 that protrudes fromthe sides of the effective TCP (or COF) 42.

FIG. 5 is a plan view showing of a base TCP (or COF) provided with aneffective TCP (or COF) according to a third exemplary embodiment. Asshown in FIG. 5, even when no sprocket hole is provided in a dummy areaof a base film 82, the effective TCP (or COF) 42 has a horizontal widthequal to the horizontal width (i.e., 35 mm) of a base TCP (or COF) 80.In this exemplary embodiment, the base film 82 may be delivered by arolling system.

In both the second and third exemplary embodiments, the effective TCP(or COF) 42 includes the extended portion 46 extended into the edges ofthe base TCP (or COF) 70/80 in the horizontal direction as shown inFIGS. 4 and 5, thereby enlarging an effective area for forming theoutput pads OP of the effective TCP (or COF) 42 on the base TCP (or COF)70/80. Thus, the horizontal width (i.e., 35 mm) of the base TCP (or COF)70/80 becomes an effective horizontal width of an area for forming theoutput pads OP of the effective TCP (or COF) 42. Also, an area on whichthe input pads IP are to be arranged extend into the edges of the baseTCP (or COF) 70/80 like the dotted line, so that the base TCP (or COF)70/80 has the 35 mm effective horizontal width for the formation of theinput pads IP.

Accordingly, the effective area for forming the output pads OP of theeffective TCP (or COF) 42 can be enlarged without enlarging the base TCP(or COF) 70/80. As a result of the above-described arrangement, thenumber of the output channels is increased. Moreover, an output pad areahaving an effective horizontal width of 35 mm may be provided with 624to 642 output pads OP having a spaced distance of about at least 50 μmon the effective TCP (or COF) 42. Herein, these output pads OP are madeby a fine pitch forming process and an assembly process. Thus, since thenumber of the output channels is increased on the existent 35 mm baseTCP (COF) 50/70/80, the number of the effective TCPs (or COFs) 42 ofFIG. 6 is fewer than the number of the effective TCPs (or COFs) 12 ofFIG. 1.

Next, a description of applying the effective TCP (or COF) 42 accordingto any one of the above-described exemplary embodiments to the data TCP(or COF) 42 of the LCD panel 40 will be given with reference to FIG. 6.

FIG. 6 is a plan view showing a rear structure of the LCD panel 40adopting the data TCP (or COF) 42. As shown in FIG. 6, when the LCDpanel 40 has a XGA class resolution of 1024×768 pixels, it is providedwith total 3072 data lines in light of R, G and B sub-pixel included perpixel. If these 3072 data lines are intended to be driven by the dataD-IC 44 having 624(642) output channels shown in FIG. 4, then it issufficient to use 5 data D-ICs 44 and 5 data TCPs (or COFs) 42 for theLCD panel 40. Accordingly, it is possible to reduce the manufacturingcosts of the LCD panel 40 more than the related art where the data D-IC2 and the data TCP (or COF) 12 having 8×384 channels are used.Particularly, the data TCP (or COF) 42 having 624(642) output channelsis molded from the 35 mm base TCPs 50/70/80 as described above, therebyfurther reducing the manufacturing costs.

As shown in FIG. 6, the data D-IC 44 is connected to the data line ofthe LCD panel 40 via the data TCP (or COF) 42, and is connected to atiming controller (not shown) via the data TCP (or COF) 42 and the dataPCB 60. The data D-IC 44 converts a digital pixel data signal from thetiming controller into an analog pixel signal and applies the analogpixel signal to the data line. On the other hand, the gate D-IC 48 isconnected to the gate line of the LCD panel 40 via the gate TCP (or COF)49, and is connected to the timing controller via the gate TCP (or COF)49 and a gate PCB 62. The gate D-IC 48 supplies a turn-on voltage of thethin film transistor to the gate line during a corresponding scan periodwhile supplying a turn-off voltage of the thin film transistor theretoduring the remaining period under control of the timing controller.

As describe above, the chip-mounted film package, namely, the TCP (orCOF) according to the exemplary embodiments of the present invention hasan extended area for forming the output pads or has a position of thesprocket holes changed. In such an arrangement, an effective area can beenlarged without enlarging the horizontal width of the base TCP (or COF)to increase the number of the output channels of the TCP (or COF) andthereby reduce the number of the TCPs (or COFs) used in an LCD module.As a result, it is possible to reduce the manufacturing costs, andimprove productivity as well as quality per unit process.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the chip-mounted filmpackage of the present invention without departing from the spirit orscope of the invention. Thus, it is intended that the present inventioncover the modifications and variations of this invention provided theycome within the scope of the appended claims and their equivalents.

1. A chip-mounted film package, comprising: a base film including acutting line; an effective film package defined on the base film by thecutting line and including input area and output area; a driving chipmounted on the effective film package; a plurality of input padsarranged on the input area of the effective film package and connectedto the driving chip; and a plurality of output pads arranged on theoutput area of the effective film package and connected to the drivingchip, wherein the output area includes at least one extended portionthat protrudes from a side of the effective film package in a horizontaldirection of the base film.
 2. The package according to claim 1, whereinthe base film includes a dummy area outside the cutting line, and thedummy area includes a plurality of sprocket holes to deliver the basefilm.
 3. The package according to claim 2, wherein the sprocket holesare arranged along a vertical direction of the base film.
 4. The packageaccording to claim 3, wherein the at least one extended portion ispositioned between the sprocket holes.
 5. The package according to claim2, wherein the sprocket holes are arranged along a horizontal directionof the base film.
 6. The package according to claim 1, wherein theoutput area including the extended portion has a same width as that ofthe base film in the horizontal direction.
 7. The package according toclaim 1, wherein the input area includes at least one extended portion.8. A chip-mounted film package, comprising: a base film including adummy area and a cutting line, the dummy area being outside of thecutting line; an effective film package defined on the base film by thecutting line, the effective film package having input pads and outputpads; a driving chip mounted on the effective film package and connectedto the input and output pads of the effective film package; a pluralityof sprocket holes arranged in the dummy area in a horizontal directionof the base film.
 9. The package according to claim 8, wherein theeffective film package has a same width as that of the base film in thehorizontal direction.
 10. The package according to claim 8, wherein theoutput pads are arranged in an extended portion that protrudes from aside of the effective film package in the horizontal direction.
 11. Thepackage according to claim 8, wherein the input pads are arranged in anextended portion that protrudes from a side of the effective filmpackage in the horizontal direction.